No explicit time-domain simulation of the behavior of a photon-counting detector array as used in a communications link is known to exist. Instead, efforts to predict detector array behavior (and hence overall communication link performance) have relied on time-average approximations for modeling some features (e.g. blocking loss) of the detector array and have simply ignored other features (e.g. crosstalk). Furthermore, previous efforts have relied on array-average values rather than an accounting of the independent behavior of individual pixels within the array. Together, these approximations and omissions result in error in predictions of the detector array behavior and system performance. Although that error is small enough to permit confident construction of an experimental system, it is large enough to prevent complete quantitative understanding of the detector array behavior and its implications for the communication system.